Three-photon absorption in CaF2 at 248.5 nm

Abstract

Nonlinear absorption at 248.5 nm is studied with an 8 ps pulse. Two-photon absorption in fused silica and three-photon absorption in CaF2 are observed. Absorption coefficients are 8×10−11 cm/W and 2×10−21 cm3 /W2 for fused silica and CaF2 , respectively.